1. JEDI A Search for Charged-particle EDMs with Storage Rings
Seminar Cracow 2012
JEDI A Search for Charged-particle EDMs with Storage Rings
| Hans Ströher

2. JEDI – The srEDM Search at FZ Jülich
Introduction  Precision physics
Electric Dipole Moments (EDM)  TV, CPV
Physics impact  Baryogenesis, BAU
Charged particle EDMs  Storage Rings
Steps towards realization  Precursor
Outline of the talk

3. JEDI – The srEDM Search at FZ Jülich
Introduction  Precision physics
Electric Dipole Moments (EDM)  TV, CPV
Physics impact  Baryogenesis, BAU
Charged particle EDMs  Storage Rings
Steps towards realization  Precursor
Outline of the talk

4. Introduction – Big Challenges
Perception of the HEP-community: 3 physics „frontiers“

5. Introduction – Physics Frontiers
Search for
the origin of
mass („Higgs“),
SUSY
Energy
Frontiers of
Physical
Sciences
Energy frontier (LHC and possible future successors)

6. Introduction – Physics Frontiers
Search for
the origin of
mass („Higgs“),
SUSY
Energy
Frontiers of
Physical
Sciences
Cosmic
Quest for
„Dark Matter“
and
„Dark Energy“
Cosmic frontier (AMANDA, Auger, Icecube, …)

7. Introduction – Physics Frontiers
Search for
the origin of
mass („Higgs“),
SUSY
Secrets of
neutrinos
Energy
Intensity
Frontiers of
Physical
Sciences
Cosmic
Quest for
„Dark Matter“
and
„Dark Energy“
Intensity frontier (Super-beams)

8. Introduction – Physics Frontiers
Search for
the origin of
mass („Higgs“),
SUSY
Secrets of
neutrinos
Energy
Intensity
Frontiers of
Physical
Sciences
Cosmic
Quest for
„Dark Matter“
and
„Dark Energy“
(In-)stability
of the
proton
Precision
A most promising additional frontier: precision

9. Introduction – Physics Frontiers
Search for
the origin of
mass („Higgs“),
SUSY
Secrets of
neutrinos
Energy
Intensity
Frontiers of
Physical
Sciences
Cosmic
Complexity
Quest for
„Dark Matter“
and
„Dark Energy“
(In-)stability
of the
proton
Precision
A most promising additional frontier: precision

10. Introduction – Physics Frontiers
ESPP, Cracow,
September 2012
A most promising additional frontier: precision

11. Introduction – Precision Frontier
Johann
Jakob
Balmer
(1885)
Balmer
Series
 H-atom
Striving for the ultimate precision/sensitivity: example hydrogen

12. Introduction – Precision Frontier
Johann
Jakob
Balmer
(1885)
Balmer
Series
 H-atom
Willis E.
Lamb
(1947)
Lamb-shift
QED
g/2 = 1 + a/2p ~
Striving for the ultimate precision/sensitivity

13. Introduction – Precision Frontier
Johann
Jakob
Balmer
(1885)
Balmer
Series
 H-atom
Gerald
Gabrielse
(et al.)
(2008)
Electron
MDM
 SM test
(…)
V. Weisskopf: „To understand hydrogen is to understand all of physics“

14. Introduction – Precision Frontier
Adapted from:
Nature,
Vol 482 (2012)
Example: Neutron (nEDM)
Search for Electric Dipole Moments (EDM) of fundamental particles

15. Introduction – Precision Frontier
Nucleon Earth + -
1023 fm
expand
Current upper limit 
separation ~ size of a hair
1 fm
An EDM is VEEEEEE … EEERY small !!

16. JEDI – The srEDM Search at FZ Jülich
Introduction  Precision physics
Electric Dipole Moments (EDM)  TV, CPV
Physics impact  Baryogenesis, BAU
Charged particle EDMs  Storage Rings
Steps towards realization  Precursor
Outline of the talk

17. Physics – Electric Dipoles
Definition
p = q s
Charge separation creates an electric dipole

18. Physics – Electric Dipoles
Definition
p = q s
Water
molecule:
permanent
electric dipole
(has de-
generate GS
w/ different
parity)
Example:
H2O
p ~ 6 x C m ~ 4 x 10-9 e cm
Charge separation creates an electric dipole

19. Physics – Fundamental Particles
Charge
symmetric
(„round“) no
EDM
Do particles (e.g., electron, nucleon) have an EDM?

20. Physics – Fundamental Particles
Charge
symmetric
(„round“) no
EDM
EDM
(aligned
w/ spin)
T operation
creates a
different
state
Not
charge
symmetric
d < e cm
Do particles (e.g., electron, nucleon) have an EDM?

21. Physics – Discrete Symmetries
If CPT
holds,
EDM
violates CP IF
particle
has an
EDM
Motivation of
N.F. Ramsey,
E.M. Purcell
to search for
nEDM;
found no PV:
d < e cm
Violation of discrete symmetries (P and T)

22. Physics – Discrete Symmetries
C.S. Wu
et al.
(1957)
Nobel Prize
1957
Lee,Yang
… also observed in m-decay …
Parity- (P) and Charge-Parity- (CP) violation

23. Physics – Discrete Symmetries
J. Cronin,
V. Fitch
et al.
(1964)
Nobel Prize
1980
Cronin, Fitch
… also observed in other systems (B, D)
Parity- (P) and Charge-Parity- (CP) violation

24. Physics – CPV in Standard Model
CP symmetry breaking due to the weak interaction:
Cabibbo-Kobayashi-Maskawa (CKM)-matrix connects the quark weak eigenstates and the quark mass eigenstates:
CKM matrix is unitary; if Vij are not real, CP will be violated  finite area of the unitary-triangle!
No exp´tly known CPV in QCD (no reason for it; “strong CP problem”)

25. Physics – Why is CPV so interesting?
CPV in the SM points to physics we do not understand
CPV is highly sensitive to physics beyond the SM (New Physics)
CPV is accessible to a wide range of experiments
New source of CPV required for baryogenesis
Physics beyond the Standard Model (BSM)

26. JEDI – The srEDM Search at FZ Jülich
Introduction  Precision physics
Electric Dipole Moments (EDM)  TV, CPV
Physics impact  BAU, baryogenesis
Charged particle EDMs  Storage Rings
Steps towards realization  Precursor
Outline of the talk

27. Physics – Baryogenesis
(…)
Matter and antimatter in our Universe

28. Physics – Baryogenesis
Big
Bang
Early
Universe
Matter Anti-matter
Assertion: Universe „started“ with equal amounts of matter and antimatter !

29. Physics – Baryogenesis
Big
Bang
Early
Universe
Matter Anti-matter
Very soon, a slight asymmetry developed (CP- / T-violation)

30. Physics – Baryogenesis
Big
Bang
Early
Universe
Matter
anti-matter
annihilation
 photons
Matter Anti-matter
All the anti-matter annihilated with matter

31. Physics – Baryogenesis
Big
Bang
Early
Universe
Matter
anti-matter
annihilation
 photons
Today
Matter Anti-matter
Now, only matter is left over !

32. Physics – Baryogenesis
The mystery of the missing antimatter (the puzzle of our existence)

33. Physics – Baryogenesis
Ingredients for baryogenesis: 3 Sakharov conditions

34. Physics – Potential of EDMs
N. Arkani-Hamed (IAS, Princeton) at Intensity Frontier WS, USA (2011)

35. Physics – Potential of EDMs
G. Isidori at ESPP Open Symposium, Cracow (Sept. 2012)

36. Physics – Potential of EDMs
J.M. Pendlebury: „nEDM has killed more theories than any other single expt.“

37. EDMs – Ongoing/planned Searches
new
P. Harris, K. Kirch … A huge worldwide effort

38. EDMs – Why another Experiment ?
Strong CP
problem
J. De Vries … What we may learn from EDMs

39. EDMs – Why another Experiment ?
Hadron
EDMs are
complex,
richer
Strong CP
problem
Need for different EDMs to pin down the source(s)

40. JEDI – The srEDM Search at FZ Jülich
Introduction  Precision physics
Electric Dipole Moments (EDM)  TV, CPV
Physics impact  Baryogenesis, BAU
Charged particle EDMs  Storage Rings
Steps towards realization  Precursor
Outline of the talk

41. EDMs – Executive Summary
Electric Dipole Moments (EDMs) of charged particles (p,d, …):
Why ? Physics case: a fundamental question
Cosmic Baryon Asymmetry
Physics beyond the Standard Model
Highest sensitivity, discovery potential
How ? New technique: spin tracking in E-, B-fields
Polarized particles
Precision storage ring
Where ? Jülich („best place on earth“)
When ? Phases:
Ongoing: Tests at COSY
Step 1: „Precursor“ at COSY+
Step 2: Dedicated EDM ring
Spin-off ? Accelerators, instrumentation, metrology, …
A spectacular opportunity that should not be missed !

42. EDMs – Measurement Technique (I)
Particle in parallel/anti-parallel B- and E-field:
Frequency/energy difference due to EDM ( d )

43. EDMs – Measurement Technique (II)
Polarized charged particles in a storage ring:
Adapted from:
Nature,
Vol 482 (2012)
EDM
MDM
EDM ( d ) in E-field produces a minuscule torque ( spin rotation)

44. EDMs – Storage Ring Technique
Polarized charged particles in a storage ring:
 development of a transverse polarization component
EDM ( d ) in E-field produces a minuscule torque ( spin rotation)

45. EDMs – Storage Ring Technique
Spin Precession (relative to momentum): Thomas – BMT Equation:
 Pure electric ring: B = 0, „magic momentum“, only if G > 0 (p)
 Combined E- and B- ring  „all-in-one“ (p, d, 3He)
 Pure magnetic ring (COSY)  tests
„frozen spin“
EDM ( d ) in E-field produces a minuscule torque ( spin rotation)

46. EDMs – Storage Ring Projects
pEDM
all-electric ring
BNL (via DOE-NP)
Two projects: US (BNL, FNAL) and Europe (FZJ)

47. EDMs – Storage Ring Projects
pEDM
all-electric ring
FNAL (via DOE-HEP)
Accumulator
Two projects: US (BNL, FNAL) and Europe (FZJ)

48. EDMs – Storage Ring Projects
pEDM
all-electric ring
BNL, FNAL
(p,d, …)EDM
all-in-one ring (E,B)
FZJ (COSY): „JEDI“
Two projects: US (BNL, FNAL) and Europe (FZJ)

49. EDMs – Storage Ring Projects
pEDM
all-electric ring
BNL, FNAL
(p,d, …)EDM
all-in-one ring (E,B)
FZJ (COSY): „JEDI“
Critical (common) R&D projects
Spin Coherence Time ( COSY)
Polarimetry (data base) ( COSY)
Beam Position Monitoring ( RHIC)
Deflectors ( COSY)
Spin Tracking (Simulations) …
Two projects: US (BNL, FNAL) and Europe (FZJ)

50. EDMs – Sensitivity Reach
EDM search in charged baryon (systems)
pEDM
dEDM
Adapted from:
Nature,
Vol 482 (2012)
NO direct measurement for proton- and deuteron-EDM yet !

51. JEDI – The srEDM Search at FZ Jülich
Introduction  Precision physics
Electric Dipole Moments (EDM)  TV, CPV
Physics impact  Baryogenesis, BAU
Charged particle EDMs  Storage Rings
Steps towards realization  Precursor
Outline of the talk

52. EDMs – Stepwise Approach
First step: „Precursor“ Experiment (using COSY+)
 Comparison of B* = 0 (EDM effect) and E* = 0 (no EDM effect)
Stored circulating beam
RF EB-Field
Vertically polarized
beam
Polarimeter
Establish srEDM, first direct measurement ; sensitivity ~10-24 e cm

53. EDMs – Stepwise Approach
Second step: A dedicated EDM Storage Ring (with COSY as injector)
Iron-free
Copper-wound
magnets
Polarized
counter-rotating
beams
Adapted from:
Richard Talman
Cornell, Febr. 2012
Sensitivity e cm  discovery potential

54. EDMs – Summary, Conclusion
EDMs of charged particles in a Storage Ring:
Physics case: „must-do“ (complementary to LHC)
IKP is one of the (very few) places worldwide
where this can be pursued:
COSY: testbed facility
first direct measurement („precursor“)
Experience with polarized beams
Forschungszentrum Jülich (HGF):
Scientific and technological „environment“
Continuity and persistence (> 10yr project)
Cooperations:
RWTH: Physics, Engineers (JARA-Fame)
BNL (US) (pEDM, use of COSY)
PNPI (Russia), KVI (NL), Ferrara (I), Cracow (PL)
A spectacular opportunity that should not be missed !